NATS 4215 Lecture Notes - Lecture 4: Northern Pike, Konrad Lorenz, Fathead Minnow
27 Jan 2017
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Document Summary
Based on lab studies but also done in the field to back it up. Prey species: the fathead minnow (pimephales promelas: dark head on males = ready to mate. Did not cross the ocean because they are not good in salt water. Found in these three places before the continent split up: stalking predator near the shore. The pike captures and injures a minnow: minnow alarm pheromone attracts a second pike. Once the pike catches a minnow they catch it sideways: handling time = amount of time used to reposition the fish so they can swallow. When there is 1 pike present, minnow was eaten 100% of the time. Minnows can survive and recover completely following injuries that cause the release of alarm pheromones. Alarm pheromone in minnows evolved as a desperate, last-minute survival signal for the sender rather than a deliberate alarm signal for other minnows. The alarm pheromone can be used as a useful cue to other minnows!!!
